The overall objective of this Phase II research project is to isolate and test the anticarcinogenic potential of active enzyme inducing constituents in essential oils determined from Phase I and the present project. Biochemical assays will be employed to screen for new substances that induce increased level of detoxifying enzyme systems. The structures of the pure active compounds isolated from the bioassay-directed fractionation will be elucidated and the structure-activity relationships as enzyme inducers and inhibitors of carcinogenesis will be assessed. Four in vivo tumor models will be used to study the chemopreventive potential of the active compounds. The inhibition of lung and forestomach tumors in mice will be used as preliminary screening assays. Further testing of the active compounds as inhibitors of chemical carcinogenesis will be carried out using a rat breast cancer model and a mouse colon tumor model. This proposed research is designed to screen, isolate, and identify systematic manner. These potential chemopreventive agents will be marketable as research chemicals and diet supplements to reduce cancer mortality in the human population.